Conventional backpacks usually have a sack made of a flexible material and comprise a front side facing a carrier, which side is either soft or comprises a frame. Such backpacks are suitable for carrying soft and durable objects, such as clothing, but they are less suitable for many other cumbersome and fragile objects, such as papers, books, binders, portable computers, and cameras. There are particular problems when the backpack is used in connection with various activities where there is a risk that the backpack will be subjected to blows and knocks.
There are also backpacks which comprise a dimensionally stable container for holding various objects. When the backpack is formed as a dimensionally stable container, e.g. from plastic, comfort problems arise. It is uncomfortable to carry a hard container directly against one's back. There have been various attempts to solve this problem.
U.S. Pat. No. 3,902,640 discloses a backpack which is made of a semi-rigid material throughout. For ease of carrying, the front side of the backpack has been given a curved profile in order to adapt it to the back of a carrier to a certain extent. However, neither does this construction achieve a backpack which is particularly comfortable to carry, especially for individuals whose body shape deviates from the shape to which the backpack is adapted.
U.S. Pat. No. 3,679,108 discloses a rigid "backbox", which has an inflatable air cushion facing the back of the carrier. A mouldable surface is formed against the carrier, but the "backbox" becomes cumbersome and is hardly comfortable to carry for a long period of time. In addition, the construction shown presents a clear risk of the carrier being injured by sharp corners and edges of the "backbox", e.g. in the case of a fall.
SE 503,777 describes a portable storage device with a dimensionally stable container and a separate harness, which has its own dimensionally stable back piece forming a surface for the carrier in front of the container. This construction also becomes cumbersome and difficult to adapt to carriers of various body shapes and creates a risk of the carrier being injured, e.g. in the case of a fall.
The two latter constructions have the drawback that they are difficult to carry with a heavy load, since the centre of gravity ends up being low and too far behind the carrier.
Carrying objects on one's back is ergonomically correct, relatively comfortable, and less tiring than carrying objects in other ways. There is thus a need for an improved type of backpack which is easy to handle and which, moreover, enables the carrying of objects which in many situations are presently unsuitable for carrying in existing types of backpack.